diff options
Diffstat (limited to 'llvm/lib')
| -rw-r--r-- | llvm/lib/VMCore/ConstantFold.cpp | 34 |
1 files changed, 34 insertions, 0 deletions
diff --git a/llvm/lib/VMCore/ConstantFold.cpp b/llvm/lib/VMCore/ConstantFold.cpp index 44df49ce876..194a6d4d8c0 100644 --- a/llvm/lib/VMCore/ConstantFold.cpp +++ b/llvm/lib/VMCore/ConstantFold.cpp @@ -357,6 +357,22 @@ static Constant *getFoldedSizeOf(const Type *Ty, const Type *DestTy, } } + if (const UnionType *UTy = dyn_cast<UnionType>(Ty)) { + unsigned NumElems = UTy->getNumElements(); + // Check for a union with all members having the same size. + Constant *MemberSize = + getFoldedSizeOf(UTy->getElementType(0), DestTy, true); + bool AllSame = true; + for (unsigned i = 1; i != NumElems; ++i) + if (MemberSize != + getFoldedSizeOf(UTy->getElementType(i), DestTy, true)) { + AllSame = false; + break; + } + if (AllSame) + return MemberSize; + } + // Pointer size doesn't depend on the pointee type, so canonicalize them // to an arbitrary pointee. if (const PointerType *PTy = dyn_cast<PointerType>(Ty)) @@ -422,6 +438,24 @@ static Constant *getFoldedAlignOf(const Type *Ty, const Type *DestTy, return MemberAlign; } + if (const UnionType *UTy = dyn_cast<UnionType>(Ty)) { + // Union alignment is the maximum alignment of any member. + // Without target data, we can't compare much, but we can check to see + // if all the members have the same alignment. + unsigned NumElems = UTy->getNumElements(); + // Check for a union with all members having the same alignment. + Constant *MemberAlign = + getFoldedAlignOf(UTy->getElementType(0), DestTy, true); + bool AllSame = true; + for (unsigned i = 1; i != NumElems; ++i) + if (MemberAlign != getFoldedAlignOf(UTy->getElementType(i), DestTy, true)) { + AllSame = false; + break; + } + if (AllSame) + return MemberAlign; + } + // Pointer alignment doesn't depend on the pointee type, so canonicalize them // to an arbitrary pointee. if (const PointerType *PTy = dyn_cast<PointerType>(Ty)) |
